The Qinling Mountains is not only the natural boundary of southern and northern China,but also is a significant ecological barrier in the middle of China,and an important water source conservation area of South-to-North Water Transfer Project.In order to serve the ecological environment construction with scientific and accurate information,NDVI(normailized difference vegetation index),LST (land surface temperature) and ET(evapotranspiration)of MODIS datasets were used to analyze the spatiotemporal variation laws and change relations of vegetation cover and hydrothermal condition after developing ecological environment construction in the Qinling Mountains area(2001-2013).It was found that generally,only NDVI presented extremely significant increasing trend in volatility,and in farmland it was more significant than in forest-grassland.NDVI and ET in forest-grassland were higher than in farmland,but LST in farmland was higher than in forest-grassland.From the point of the spatial distribution,spatial variations of NDVI,LST and ET presented mountainous features.NDVI increased with the increase of altitude,began to decline slightly at about 2 000 m.LST presented extremely significant linear downward trend with altitude. In addition,LST dropped 0.51℃as altitude increased for every 100 m.With the increase of altitude,ET started to increase below 800 mand later flattened at 800-1 800 m,and then decreased in the end.NDVI, LST and ET changed obviously in low altitude.From 2001 to 2013,the improvement of NDVI in the Qinling Mountains area was the interactive effect of implementation of a series of ecological construction projects such as closing hill for forestation and restoring farmland into forestland and grassland.Under the background of global warming,no obvious change in LST,indicating a certain correlation with the regulation function of vegetation.The increase trend of ET caused by the improvement of NDVI,and the decrease trend of ET was associated with the decrease of solar radiation.